** FILE ** In a file photo a shop assistant waits behind frying pans with non-stick surfaces at a store in Beijing Tuesday July 13, 2004. A controversial chemical used by DuPont Co. to make the nonstick substance Teflon poses more of a cancer risk than indicated in a draft assessment by the Environmental Protection Agency, an independent review board has found, in a report released Monday, June 27, 2005. (AP Photo/Greg Baker)